Support numeric chain IDs in URL parameter

[PaulRBerg]

Problem

Currently, the chain URL parameter only accepts chain slugs (e.g., ?chain=base, ?chain=ethereum). This requires users and integrators to know the specific slug for each chain, which can vary between applications.

For example, this works:

https://app.uniswap.org/swap?chain=base

But this doesn't:

https://app.uniswap.org/swap?chain=8453

Proposed Solution

Accept numeric chain IDs as an alternative to chain slugs in the chain URL parameter. The parser could check if the value is numeric and resolve it to the appropriate chain, falling back to slug matching for non-numeric values.

This would allow both formats:

• ?chain=base (existing behavior)
• ?chain=8453 (proposed addition)

Use Case

• Deep linking: Other apps and wallets often work with chain IDs natively, making it easier to construct URLs programmatically
• Consistency: Chain IDs are standardized (EIP-155), while slugs can differ between applications
• Developer experience: Reduces the need to maintain a mapping table when integrating with Uniswap

[ChetanReddyC]

Hey @PaulRBerg — I’m planning to work on a PR for this using the approach you proposed. I’ll comment here if I run into any questions.